Fourdrinier



Sept. 6, 1955 s. c. SULLIVAN FOURDRINIR 3 Sheets-Shee l Fild June 3, 1953 /N VEN TOR y/vesfer C'. .SUM/Var? ATToRA/Yg Sept. 6, 1955 s. c. SULLIVAN FOURDRINIER 5 Sheets-Sheet 2 Filed June 3, 1953 www A 'r TOR/VE v5 SePt- 6, 1955 s. c. SULLIVAN 2,716,927

FOURDRINIER Filed June 3, 1953 3 Sheets-Sheet Z5 Mv/M A T TOR/VE Ys United States PatentO FOURDRINIER Sylvester C. Sullivan, Hudson Falls, N. Y.

Application June 3, 19573, Serial No. 359,283

6 Claims. (Cl. 92-44) My invention relates to paper making and particularly to improvements in papermaking machines of the Fourdrinier type.

In a Fourdrinier, the stock from which the paper is to bel formed and which consists of cellulose fibers suspended in water, is delivered to what is called a head box, from is delivered thereon from the head box, the discharge velocity of the stock through the slice is maintained at approximately the same velocity as that at which the wire is traveling. This takes care of the bers in the stock which are adjacent the wire, but the upper surface of the stock moves in contact with the still air above the wire which offers resistance to its movement with the wire and reduces its velocity as compared with the velocity of the wire. On high speed machines, the tendency of the air over the wire to retard the velocity at which the upper surface of the stock is traveling is a factor which limits the speed at which the machine can be run and still obtain acceptable formation of the paper. As the speed of the wire is increased, the discharge velocity of the stock must also be increased, and the inertia of the discharged stock carries it for some distance along with the wire "i before the force of gravity can draw off a sufficient amount of water to cause the sheet to form. It is in passing through this space or distance that the velocity of the upper surface of the stock is retarded by its contact with the air. This differential in velocity between the upper and lowersurfaces of the sheet of stock causes those fibers which are initially being carried in a vertical or nearly vertical position in the water to align themselves with the direction of travel of the wire. This is evidenced by the fact that most sheets of paper as formed on the present machines can be torn easily and in a fairly straight line in a direction in which the stock was moving when the Sheet was formed, while the resistance to tearing in a direction at right angles thereto is substantially greater, and it is practically impossible to make a straight tear across the sheet in this direction. Furthermore, the tensile strength of samples taken longitudinally is greater than of those taken transversely.

The principal objects of my invent-ion -are to provide improvements in papermaking machines of the Fourdrinier type which will provide a more perfect format-ion of the paper sheet on the wire; which will substantially increase the speed at which a Fourdrinier may be operated; which will reduce the number of'suction boxes and in some cases eliminate them entirely, thus lengthening the useful life of the' wire by reducing or eliminating `the fric- 2 tional wear thereon caused by `running over the suction boxes; which will effect a more complete drainage of water from rthe web of paper as it is formed on the wire; and, by reason of which, the length of the wire, and therefore the cost thereof, may be reduced.

I accomplish these and other objects, which will be apparent as the description of my invention proceeds, by means of the novel elements and the combinations and arrangements thereof described below and illustrated in the accompanying drawing in which- Fig. 1 is a fragmentary, diagrammatic side elevation of the wetend of a F ourd'riniermachine;

Fig. 2 is a fragmentary, enlargedside elevation of a Fourdrinier showing a portion of the wire, three of the 'table rolls, and how my invention is applied thereto;

Fig. 3 is afragmentary section through Fig. 2 in the plane 3 3;

Fig. 4 is a fragmentary plan view drawn to an enlarged scale of that portion of Fig. l at the righty hand end thereof;

Fig. 5 is a section of Fig. 4 in the plane l5 5;

Fig'. 6 is a diagrammatic side elevation showing a portion of the wire and slice, the breast roll and how the various elements of my invention which supply and control the velocity of the a-ir in the enclosure are applied tothe Fourdrinier;

Fig. 7 is a wiring diagram illustrating one arrangement of the elements which synchronizes the air velocity above the wire with the velocity of the wire itself;

` Fig. 8k is a fragmentary, diagrammatic side elevation `of the equipment for automatically operating the air outlet damper; and

Fig. 9 is a wiring diagram illustrating one arrangement of the elements which automatically operate the air outlet damper, thus controlling the static pressure of the air within the enclosure.

Referring to the drawing and iirst to Figs. l, 2, 3 and 4, 1 is the wire, 2 is the breast roll, and 3 is the lower couch roll over/which the wire runs as a belt. 4 are the table rolls upon which the wire rides, and 5 is the slice through which the stock is discharged on the wire.

In general I propose to enclose the wire at the top and sides thereof, and to maintain a current of air flowing through the enclosure thus formed in the same direction and a-'t the same velocity as the wire is traveling, and exerting a static pressure upon the stock beneath it. The enclosure extends from the slice to the couch roll 13 where the paper' formation is completed. Thus, 6 is the top of the enclosure over the wire, 7 vis one-of the sides which have portions-S'underlying the marginal edges of the' wire.

Referring now more particularly to Fig. 6, 9 is a blower which is adapted to force air downwardly through the tube 10 and through the enclosed space between the wire 4 and the top of the enclosure 6. In order to provide for the egress of the air after it has passed through the enclosure, I provide an adjustable damper l1 which can be automatically regulated by means of a worin' wheel 14 (see Fig. 4) and a worm and shaft cooperatingtherewith (see Fig. 8). In order to prevent the escape of air other than through the damper 11, I provide a sort of doctor I2 which' runs in contact with the couch roll 13.

In order' to synchroniie the velocity of air flow through the enclosure above the wire with the velocity ofthe wire itself, I provide an electric tachometer 15 which is here shown as driven by a belt 16 from the breast roll 2 so that the' speed of the tachometer is proportional to the speed of the breast roll and the speed of the wire. The tachorneter' is a generator which produces an electric current at a potential which varies directly with its speed or, in other Words-,- with thespeed of the wire. 17 is an electric anemoiete'r'having apropeller 18 which is driven ing through the enclosure above the wire and the speed or velocity of the wire itself, they may be calibrated, as explained below, so that when the air speed is equal to the wire speed the voltages are identical. v

21 in Fig. 6 is a potential comparing unit, theA details of which will be explained below in connection with the wiring diagram shown in Fig. 7. 22 and 23 are the power lines from which power is drawn to drive the reversible motor 24 which operates the speed control device 25, and 26 is a variable speed driving motor or mechanism for the blower 9. blower is automatically regulated by reducing or increasing the rate at which the impeller of the blower is rotated, which, in turn, is controlled by the reversible motor 24.

Referring now more particularly to Fig. 7, there is here shown in a diagrammatic way the tachometer generator 15, the anemometer generator 17, the voltmeters or air and wire speed indicators 19 and 2i), respectively, the main power lines 22 and 23, and the reversible motor 24. 2'7 is a rectifier through which current can flow only to the right, and 28 is a second rectifier through which current can only iiow to the left. 29 and 39 are relays, and 3l and 32 are variable resistances. The resistances 31 and 32 are adjusted so that, when the speed of the wire and the velocity of the air moving through the enclosure over the wire are the same, the voltages at the Assuming that the speed of the wire becomes greater than the velocity of the air, in which case the voltage at A becomes greater than at B and C. The rectifier in the line A C prevents the dow of current from AC, but the rectiier 27 allows current to iiow from A-B. Current iiowing in the line A B energizes the relay 29 which L closes to form an electrical circuit from the power lines (assuming the switch 23 to be closed) to the reversible motor which` in turn increases the speed of the blower 9, to increase supply of air to the enclosure. When the velocity of the air reaches the speed of the wire, the voltages at A, B and C become equal again and the relay 29 is cle-energized and breaks the circuit through the reversible motor 24. f

When the velocity of the air exceeds the speed of the wire, the voltage at B and C is greater than at A. Since the rectifier 2'7 prevents current flowing from B to A, but the rectifier 28 allows current to ow from C to A, the relay 3S is energized and closes a circuit through the other field of the reversible motor 24 tending to cause it to rotate in the opposite direction, and operate a rheostat or a mechanical variable speed device to cut down the speed of the blower, and thus reduces the Velocity of air over the Wire. I

From the foregoing, it wiil be evident that I have provided a means whereby the velocity of air flowing through .'.1'

the enclosure over the wire is maintained substantially the same as the velocity at which the wire itself is moving thus eliminating the eifect of still air over the stock on the wire, preventing the alignment of the bers with the wire, and effecting the deposit of the fibers on the wire in The volume of air delivered by the (lll 35 contains the electric control equipment shown in detail in Fig. 9. 36 is the electric power supply line and switch. 37 is a case enclosingthe worm and gear which operate the air outlet damper (see 14, Fig. 4). 38 is a reversible motor which operates the above mentioned worm and gear, and 39 represents the three wires from the control equipment to the reversible motor.

Fig. 9 shows the connections between the various elements of the system to control the static pressure of the air within the enclosure 6 above the wire. 40 is the `pressure element which rotates the indicating needle 41 proportional to the static pressure in the enclosure. Indicating needle 4l is of electric current conducting material and makes contact with terminals 42 and 43 as described below. These terminals are insulated from one another and so arranged that they may be moved simultaneously along the arc described by the contact point of needle 41. Contact between needle 41 and terminal 42 closes control circuit D, while contact between needle 41 and terminal i3 closes control circuit E. 44 is a transformer to furnish low voltage electric current to control circuits D and E. 45 and 46 are relays, operated by circuits D and E respectively. 47 and 48 are limit switches in the power circuits 39 to the reversible motor 38. These limit switches disconnect the power supply to the reversible motor when the outlet damper is in either fully closed or fully opened position.

The operation of the system is fully automatic to maintain a predetermined static air pressure in the enclosure above the wire. Terminals 42 and 43 are moved manually so that the midpoint between them is set on the scale 49 representing the desired static pressure. With switch 36 closed, transformer 44 supplies low voltage current to control circuits D and E. When the static pressure is below the setting of the midpoint between terminals 42 and 43, needle 41 is in contact with terminal 42. This closes control circuit D, which in turn closes relay 45 arid the power circuit through limit switch 47 to the reversible motor to close the outlet damper. lf at that time the damper is fully closed, limit switch 47 isI open and no movement takes place. As the static pressure builds up needle 41 rotates clockwise until it passes the setting of the midpoint between terminals 42 and 43. When it comes in contact with terminal 43, control circuit E is ciosed. This closes relay 46 and the power circuit to reversible motor 3S which opens the outlet damper sutiiciently to cause the needle 41 to turn counterclockwise until it breaks contact with terminal 43. While the needle 41 is between terminals 42 and 43, both control circuits D and E are open and no movement of the outlet damper takes place. Y

What l claim is:

l. ln a Fourdrinier machine comprising a wire and a slice, the combination with means enclosing the upper side of saidwire from the slice throughout a Zone within which a web of paper on said wire is substantially completely formed, of a blower for creating and maintaining a ow of air through said enclosing means in the direction of movement of said wire, means for measuring the velocity of air ow through said enclosing means, means for measuring the velocity of said wire, and means controlled bythe differential in said velocities for controlling the speed of said blower.

2. In a Fourdrinier machine comprising a wire and a slice, the combination with means enclosing the upper side of said wire from the slice throughout a zone Within which a web of paper on said wire is substantially competely formed, of a blower for creating and maintaining a flow of air through said enclosing means in the direc tion of movement of said wire, an electric motor for driving said blower, an electric generator driven by theair owing in said enclosing means, a second electric generator, means for driving said second generator at a rate proportional to the speed of said wire, means for adjusting the voltage developed by atleast one of said generators so that it is substantially equal to the voltage developed by the other generator, when the air velocity through said enclosing means is substantially equal to the speed of said wire, and means controlled by differentials in said voltages for controlling the velocity of air ow through said enclosing means.

3. In a Fourdrinier machine comprising a wire and a slice through which stock is delivered to said wire, the combination with means enclosing the upper side of said wire from the slice throughout a zone within which a web of paper on said wire is substantially completely formed, of means for creating and maintaining a ow of air through said enclosing means in the direction of movement of said wire, of a first means for generating an electric current at a voltage varying directly with the velocity of said air flow, a second means for generating an electric current at a voltage varying directly with the speed at which said wire is moving, means for adjusting said voltages so that they are equal when the velocity of said air flow is equal to the speed of said wire, and means controlled by the differentials thereafter occurring in said voltages for maintaining the velocity of s aid air ow substantially equal to the speed of said wire.

4. In a Fourdrinier machine comprising a wire and a slice through which stock is delivered to said wire, the combination with means enclosing the upper side of said wire from the slice throughout a zone within which a web of paper on said wire is substantially completely formed, of a blower for creating and maintaining a ow of air through said enclosing means in the same direction as the movement of said wire, of a propeller rotatably mounted within said enclosing means and driven by said air flow; a generator driven by said propeller and delivering an electric current at a voltage varying directly with the speed at which it is driven; a second generator delivering an electric current varying directly with the speed at which it is driven; means for driving said second gen-y erator at a speed directly proportional to the speed of said wire; the voltages at which current is delivered from said generators being substantially equal when the velocity of said air flow is substantially equal to the speed of said wire; means for varying the velocity of said air ow; and means, including a reversible motor controlled by differentials in the voltages of the current delivered by said generators, for maintaining said velocity substantially equal to the speed of said wire.

5. In a Fourdrinier machine comprising a wire and a slice, the combination with means enclosing the upper side of said wire from the slice throughout a zone within which a web of paper on said wire is substantially completely formed; of means for maintaining a flow of air through said enclosing means in the same direction as saidl wire moves; a movable damper at the end of vsaid enclosing means for the discharge of said air therethrough; and means controlled by the air pressure within said enclosing means for moving said damper to maintain a substantially constant air pressure within said enclosing means.

6. In a Fourdrinier machine comprising a wire and a slice, the combination with means enclosing the upper side of said wire from the slice throughout a zone within which a web of paper on said wire is substantially completely formed, of a blower for creating and maintaining a llow of air through said enclosing means in the direction of movement of said wire, means for measuring the velocity of air flow through said enclosing means, means for measuring the velocity of said wire, means controlled by the differential in said velocities for controlling the speed of said blower; a movable damper at the end of said enclosing means for regulating the discharge of air owing through said enclosing means; and means controlled by the air pressure within said enclosing means for varying the opening of said damper and maintaining said pressure substantially constant. i

References Cited in the tile of this patent UNITED STATES PATENTS 645,081 Fletcher Mar. 13, 1900 1,563,095 Lewtliwaite Nov. 24, 1925 2,186,761 Malkin Ian. 9, 1940 2,357,201 Hornbostel Aug. 29, 1944 2,540,301 Staege Feb. 6, 1951v 2,616,802 Kehoee et al. Nov. 4, 1952 2,664,033 Hornbostel et al. Dec. 20, 1953 FOREIGN PATENTS 535,589 Germany Oct. 14, 1931 423,435 Great Britain Jan. 28, 1935 254,246 Switzerland Dec. 16, 1948 

